What Happens To Your Old Motor Oil?

January 21st, 2016

If you ever changed your own oil, you know it’s pretty nasty stuff. Smelly, dirty, filled with acids, soot and unburned hydrocarbons, a quart of used motor oil can Oil Changes in Lafayette LApollute up to a quarter-million gallons of water if it makes its way to the water table. That means that the waste oil from a single oil change can contaminate more than a million gallons of water, which is a year’s supply of water for about 50 people. And if you do change your own oil, you end up with five quarts of the stuff…and before long, that five quarts will turn into several gallons that all need to be dumped off at a recycling facility. Nationwide, about 1.3 billion gallons of used motor oil are collected and recycled every year.

As nasty as used motor oil is, though, the good news is that there are plenty of uses for it once it’s been drained from your car’s crankcase.

Obviously, used motor oil has plenty of impurities that need to be filtered out. Virgin motor oil is degraded by the engine’s heating/cooling cycles, and starts to pick up carbon, acids, metal particles, benzene, lead, arsenic, zinc, cadmium and other contaminants just from being in the engine for several thousand miles. That’s not even thinking about the water, dirt, transmission fluid, coolant and other junk that gets mixed in with the used oil before it makes it to the recycling collection tanks.

The oil is first tested to determine whether it will even be suitable for recycling. It is then dehydrated, separating the water out of the oil – used motor oil is actually about 5-7 percent water. Any ethylene glycol antifreeze can be captured out of the oil and used as recycled antifreeze. Vacuum distillation separates the lighter oil elements from the heavy base oil, then hydrogenation removes any polymers and other chemical compounds from the oil.

Final oil separation, known as “fractionating,” is what splits the used motor oil into three separate grades:

·         Light viscosity lubricants, used for general lubrication (i.e. refrigeration lubricant, light machine oil)

·         Low viscosity lubricants for industrial (i.e. machine shops) and automotive use

·         High viscosity lubricants for heavy-duty applications (i.e. thick grease for machinery)


Aside from being used as lubricants and greases, motor oil can be repurposed as fuel for blast furnaces, boilers or marine engines, and can be used as asphalt extender, roofing tar, and other industrial applications. The best of what comes from the re-refining process can then be mixed with detergents, anti-foaming agents, dispersants and other additives and sold as motor oil again. Tests show that re-refined motor oil performs as well as virgin mineral-based oil when it comes to lubrication and protection.

When you come to Chabill’s Tire & Auto Service for an oil change, you can be confident that your used motor oil will be recycled properly. It’s our commitment to you and to the environment!

What’s your motor oil looking like? Is it nice and honey-colored, or is it the color of black coffee? What’s your odometer reading say? If it’s time for an oil change, make an appointment with us at Chabill’s Tire & Auto Service and let us get your car taken care of today! 

  Posted in: Auto Repair 101